Patent EP-1715341-A1 (EP)
Inventor: KLAPPROTH HOLGER DR
IPC: G01N33/543
Filed: 2005-04-04
Abstract: Determining concentrations of at least two ligands presumed to be present in sample, where the ligands are bond-specific for first and second receptors, is new. Determining the concentrations of at least two ligands presumed to be contained in a sample for analysis, where a first ligand is bond-specific for a first receptor (6) and a second ligand is bond-specific for a second receptor, where the first receptor is immobilized on at least first test site (5) and the second receptor is immobilized on at least second test site on a substrate, comprises: (a) mixing sample with a competitor that is bond-specific to second receptor to obtain a mixture, in which the competitor is present in predetermined concentration; (b) contacting mixture with substrate so that first ligand can bind to first receptor and second ligand and/or competitor can bind to second receptor; (c) removing components of the mixture that are not bound to an immobilized receptor from the substrate; (d) generating a first metering signal relative to the concentration of the first ligand bound to the first receptor and a second metering signal relative to the concentration of the competitor bound to the second receptor; and (e) determining the concentration of the first ligand in the sample with reference to the first metering signal and the concentration of the second ligand in the sample with reference to the second metering signal and the known concentration of the competitor in the mixture. Independent claims are included for the following: (1) a device for determining the concentrations of at least two ligands in a sample for analysis, with a metering chamber (2), comprising at least one inlet opening (3) and a drain opening, where the metering chamber has a substrate on which a first receptor and a second receptor are immobilized on a first test site and a second test site, respectively, where the first receptor and the second receptor are bond-specific for a first ligand and a second ligand, respectively, where a first sensor to capture a first metering signal relative to the concentration of the ligand bound to the first receptor and a second sensor are arranged on the first test site and the second test site, respectively, where the device comprises a mixing device for mixing the sample with a competitor that is bond-specific to the second receptor, which mixing device is connected to an infeed opening for the sample and a receiving space containing the competitor, that the mixing device comprises an outlet opening for the mixture comprising the sample and the competitor, the outlet opening being connected to the inlet opening of the metering chamber, that the mixing device is configured so that the competitor is present in the mixture in a predetermined concentration, that the second sensor is configured to capture a second metering signal relative to the concentration of the competitor bound to the second receptor and is connected to a computer, which computer is configured to determine the concentration of the second ligand in the sample from the second metering signal and from the concentration of the competitor in the mixture; and (2) kit for determining the concentrations of at least two ligands presumed to be contained in a sample for analysis, comprising: (a) a device in which the first sensor is configured as a sensor for measuring a redox potential, detection antibody that is bond-specific to the first ligand and marked with an enzyme and at least two chemicals between which a chemical redox reaction takes place upon contact with the enzyme; (b) device, a detection antibody that is bond-specific to the first ligand and marked with an enzyme, and a chemiluminescent substrate, in which a chemical reaction is triggered upon contact with the enzyme, in which reaction a beam of light is emitted to which the first sensor is sensitive; (c) detection antibody that is bond-specific to the first ligand and marked with a marker that can be excited to emit a beam of light when irradiated with excitation radiation, in which the first sensor is sensitive to the beam of light and not sensitive to the excitation radiation, and a radiation source arranged on the first test site for emitting the beam of light; (d) a device, in which the competitor is marked with an enzyme and in which the second sensor is configured for measuring an electric redox potential, and at least two chemicals, between which a chemical redox reaction takes place upon contact with the enzyme; or (e) a device in which the competitor is marked with an enzymes, and a chemiluminescent substrate, in which a chemical reaction is triggered upon contact with the enzyme, in which reaction a beam of light is emitted to which the second sensor is sensitive.